*{
    margin: 0;
    padding: 0;
    /*标准盒子*/
    /*box-sizing: border-box;*/
}
li{
    list-style: none;
}
a {
    text-decoration: none;
}
.header {
    background-color: black;
    width: 100%;
    height: 50px;
}

.header .menu {
    display: flex;
    height: 100%;
    line-height: 50px;
    max-width: 600px;
    padding: 0 20px;
}
.header .menu li{
    height: 100%;
    color: white;
}
.header li:hover {
    background-color: #007bff;
    transition: color 0.5s;
}
.header .menu li a {
    font: bolder normal 16px Source Sans Pro;
    color: #fff;
    padding: 14px 15px;
}
.header .menu li p{
    font: bolder normal 16px Source Sans Pro;
    color: #fff;
    padding: 14px 15px;
}
.header .menu .用户设置的下拉菜单{
    display: none;
    position: absolute;
    background: black;
    /*border-radius: 5px;*/
}
.header .menu .用户设置的下拉菜单 li{
    padding: 0 0.5em;
    text-align: center;
}
.header .menu .用户设置:hover .用户设置的下拉菜单{
    display: block;
}
body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 20px;
    background-color: #f5f5f5;
}
.标题{
    color: #333;
    text-align: center;
    align-items: center;
    border: blueviolet solid 2px;
    box-shadow: 10px 10px 20px rgba(0, 0, 0, .5);
    margin: 500px;
    margin-top: 30px;
    margin-bottom: 100px;
    padding-top: 20px;
    background-color: white;
    border-radius: 20px;
}

.内容 {
    margin-top: 20px;
    padding: 10px;
    background-color: #fff;
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}
.内容 h2{
    text-align: center;
}

table {
    width: 100%;
    border-collapse: collapse;
}

table td {
    padding: 8px;
    border-bottom: 1px solid #ddd;
}

table tr:first-child {
    font-weight: bold;
}
.图片{
    margin: 400px;
    margin-top: 20px;
    margin-bottom: 20px;
    border: 5px solid #333333;
    border-radius: 15px;
}
.图片 img {
    display: block;
    margin: 0 auto;
    max-width: 100%;
    height: auto;
}
.back {
    border: none;
    text-align: center;
    display: block;
    height: 30px;
    width: 200px;
    padding: 30px;
    padding-top: 0;
    font: 900 20px '';
    border-radius: 10px;
    margin: 20px auto;
    color: #fff;
    letter-spacing: 3px;
    background-image: linear-gradient(
            to left,
            #fd79a8,
            #a29bf6
    );
}